Re: [PATCH 2/4] Tweak diff output further to make it a bit less distracting.

On Tue, 17 May 2005, Petr Baudis wrote:

quoted

	diff -git a/kernel/sched.c b/kernel/sched.c.old
	rename kernel/sched.c kernel/sched.c.old

Actually, if the git diff format is fixed, do we even need the explicit
rename line? It could be enough if the filenames on the diff line would
be just different. Or you want it because of clarity?

Yes, it's something we can glean from the header itself (or the ---/+++
lines), but I'd prefer it just to make things really obvious. Especially
as all the other pathnames involved (both on the "diff" header line and on
the ---/+++ lines) are in non-canonical -p1 format. So the "rename" line
would be the only one that is actually in canonical form.

There's also a real technical reason for this: since the rename format
would not be a valid patch for a traditional "patch" program, and if we
ever want to actually teach "patch" to handle it, we really need to be
explicit. There are tons of traditional patches around that say

	diff -Nur a/kernel/sched.c.old b/kernel/sched.c
	--- a/kernel/sched.c.old
	+++ b/kernel/sched.c
	...

and clearly the above is _not_ a rename from "sched.c.old" to "sched.c",
so if we want to teach "patch" about the magic git rules, we'd have to
have something unambiguous that a GNU patch maintainer might be willing to
trigger on. The combination of the "diff -git " and "rename" markers might
be such a thing.

So it's a combination of clarity, canonical names, and "patch" issues.

		Linus